The present invention relates to telecommunications, and particularly, to providing telephony services from disparate media gateway controllers for a single media gateway.
There is a growing interest in the convergence of the public switched telephone network (PSTN), the Internet and other internets and intranets. The convergence of these networks requires technology that facilitates interworking in a uniform and effective manner. The next generation of unified networks will provide an open and scalable architecture to accommodate multiple vendors and protocols under a single communication scheme. At the moment, there are several obstacles to providing a scalable, unified network incorporating the PSTN, Internet, cable systems, and wireless systems, among other existing and further networks.
The traditional PSTN provides constant bandwidth streams of information between users. These media streams travel over dedicated circuits, typically between telephones. Circuit-switched networks were originally designed for carrying voice traffic and handling calling patterns, but, with the emergence of the Internet, are now handling significant amounts of data traffic. The data traffic occupies a significant amount of the bandwidth of the circuit-switched network as the data makes its way to Internet protocol (IP)-based networks. In addition, the IP-based networks are now carrying significant amounts of data that relate to voice, fax and video in addition to conventional data. Further, advances in cable and wireless technologies are requiring cable networks and wireless networks to efficiently interact with the PSTN and the IP-based Internet.
Since packet switching networks appear to be the common thread between all of the many networks, there is a need to seamlessly interwork all networks and individual endpoints connecting to these networks. The interface between networks, as well as between a network and individual endpoints, is provided by media gateways. Media gateways require interaction with media gateway controllers to provide decision-making and coordination with other media gateways.
The primary responsibility of the media gateway is to allow media of various types, including voice, fax, video and data to be transported in a unified network. Typically, the media must be transportable both as packets in an IP-based network and as digital or analog streams in a circuit-switched network. In such applications, the media gateway provides bi-directional communications between a circuit-switched network and media-related elements associated with an IP network. Media gateways generally interact with end users in telephony applications or with other media gateways to facilitate such applications. The media gateway controllers provide media gateways with instructions on interconnecting two or more telephony or IP elements in order to exchange information. For example, media gateway controllers instruct media gateways on how to set up, handle and terminate media flows, such as Internet connections or telephone calls.
Existing media gateways are very rigid in structure and configuration. Typically, all endpoints associated with a media gateway are served by a single media gateway controller. Although the H.248 protocol standard for packet telephony set forth by the International Telecommunications Union and the Internet Engineering Task Force indicates that groups of endpoints within a single gateway may be handled by separate media gateway controllers, there is a need for increasing the flexibility of handling endpoints by multiple media gateway controllers and providing an efficient way of allocating endpoints with one or more media gateway controllers. Given the present standards and architectures, it is likely a given media gateway will have only a small number of defined groupings of endpoints capable of being served by different media gateway controllers. Thus, a single media gateway will likely be controlled by only a very small number of media gateway controllers.
In order to maximize the service and selection to end users, it is desirable to enable individual lines or endpoints of a media gateway to be supported by any media gateway controller throughout the network. Current architectures do not allow subscribers at any given endpoint to receive media and data services provided by media gateway controllers operated by different service providers, nor do they allow media gateways to interact with call servers supporting variations in communication and media control protocols.
The existing rigidity in media gateways prevents 1) dynamically changing associations between endpoints and media gateway controllers to facilitate efficient changes in service for users in a given endpoint; 2) easily scaling the system to accommodate additional endpoints; and 3) readily reassigning and distributing endpoints to other media gateway controllers in case of congestion or failure of a media gateway controller.
As such, there is a need for a more efficient and flexible architecture allowing dynamic association of media gateway endpoints with any number of media gateway controllers.
The present invention addresses the failings of the state-of-the-art by providing an architecture for a media gateway to identify and register with multiple media gateway controllers for various types of voice and data services, along with having the media gateway appear to each of these media gateway controllers as a single, dedicated control entity. A logical layer, referred to as a virtualizer, is associated with each media gateway and appears to the media gateway as a single media gateway controller. To each media gateway controller the virtualizer supports, the virtualizer appears as a single media gateway. In essence, the virtualizer is a protocol manager and message router. The virtualizer supports the registration of multiple media gateways and then creates virtual gateways based on requirements of the media gateway controllers serving these virtual gateways. Preferably, subscribers associated with endpoints handled by the media gateway are grouped into a virtual gateway being served by a select media gateway controller or group thereof.
The virtualizer interacts with the network manager to determine the media gateway controllers it should register against, depending on the type of services requested by the subscribers. As events are reported from the media gateway, the virtualizer routes resulting messages to the appropriate media gateway controller. Conversely, the media gateway commands received from the media gateway controller are forwarded to the appropriate media gateway. The virtualizer may translate commands or event reports as required in the event the media gateway or media gateway controller are not using identical versions of a particular protocol.
The virtualizer and the virtual gateways associated therewith may be incorporated in a media gateway, a media gateway controller, or a third device coupled to an accessible network. Importantly, the system handling the virtualizer operation is configured to dynamically associate endpoints for one or more gateways as a virtual gateway and arrange the necessary relationship with one or more media gateway controllers. The dynamic handling and creation of these relationships allows efficient controlling of individual lines and endpoints to be supported from any media gateway controller in the network. Further, subscribers at any given endpoint may receive media and data services from multiple service providers at any given time. The ability to dynamically change associations allows for efficient scaling of the system to add media gateways and endpoints to existing, as well as new, media gateway controllers. Further, the virtualizer may support a secondary or backup association with a media gateway controller in case the primary media gateway controller fails or becomes overly congested.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon reviewing the following description of the preferred embodiments of the invention in conjunction with the accompanying figures.